prevent errors from erlang.el

In erlang.el, add a line to evaluate the cl package at compile time so that
the use of the block macro (such as on line 3750), which is an alias for
cl-block, is evaluated correctly when erlang.el is compiled. Also modify
comparisons against (point) in functions erlang-electric-lt and
erlang-after-bitsyntax-close so that typing the characters '<' and '>'
(without the quotes) at the beginning of a buffer does not cause errors.

Thanks to user leo2007 in the #erlang channel on IRC for reporting these
problems and providing fixes.